Collie was released by the Colts in February after playing his first four years in the NFL in Indianapolis. He had his 2012 season cut short after playing just one game when he suffered a torn patella tendon. Prior to that, Collie had suffered multiple concussions, making teams wary of signing the wide receiver.

"I went through a very thorough examination with my head and cleared everything," Collie told the San Jose Mercury News. "To be honest, I don't think I needed those tests. I knew where my head was at."

San Francisco, who is dealing with a variety of injuries with its wide receivers, also signed free-agent receiver Lavelle Hawkins, who practiced with the team Friday night as well. According to 49ers.com writer Taylor Price, both Collie and Hawkins participated in an 11-on-11 drill, running with the third team offense.

The Sacramento Bee initially reported that Collie worked out for San Francisco on Thursday, after also trying out for the team in mid-June. In addition, he had worked out for the Patriots, Jets and Dolphins.

The 49ers are down proven starting wide receivers Michael Crabtree and Mario Manningham, who both began training camp on the physically unable-to-perform list. Crabtree underwent surgery for a torn Achilles in May and Manningham went down with a torn ACL near the end of the 2012 regular season.

In Collie's rookie NFL season, he posted 60 catches for 676 yards and seven touchdowns during the regular season.

In his second year, Collie again found success early on, as he caught 44 passes for 493 yards and six touchdowns in the season's first six weeks. But a pair of concussions, including a second in Week 15, put Collie on injured reserve.

Since then, however, Collie has had just 55 catches for 560 yards and one touchdown, a stark contrast to the success he enjoyed in the early part of his career.